Directional audio systems work by spatially filtering received sound so that sounds arriving from the look direction are accepted (constructively combined) and sounds arriving from other directions are rejected (destructively combined). Effective capture of sound coming from a particular spatial location or direction is a classic but difficult audio engineering problem. One means of accomplishing this is by use of a directional microphone array. It is well known by all persons skilled in the art that a collection of microphones can be treated together as an array of sensors whose outputs can be combined in engineered ways to spatially filter the diffuse (i.e. ambient or non-directional) and directional sound at the particular location of the array over time.
The prior art includes many examples of directional microphone array audio systems mounted as on-the-ear or in-the-ear hearing aids, eye glasses, head bands, and necklaces that sought to allow individuals with single-sided deafness or other particular hearing impairments to understand and participate in conversations in noisy environments. The various challenges of the implementing directional audio systems into wearable garments include awkward or inflexible mounting of the microphone array, hyper-directionality, ineffective directionality, and inconsistent performance. When using the audio system in its bi-directional capacity and speaking into the microphone, it becomes crucial to pinpoint the sound source with accuracy in order to filter out the ambient noise surrounding the speaker. This is especially important for individuals working in high ambient noise conditions, such as flight decks or airport tarmacs for example.
A review of the prior art reveals the following wearable microphone array devices. U.S. Pat. No. 7,877,121 issued to Seshadri et al. discloses at least one wearable earpiece and at least one wearable microphone.
U.S. Pub. No. 2011/0317858 to Cheung discloses a hearing aid frontend device for frontend processing of ambient sounds. The frontend device is adapted for wearing use by a user and comprises first and second sound collectors adapted for collecting ambient sound with spatial diversity.
World Pat. No. 8,111,582 issued to Elko discloses a microphone array, having a three-dimensional (3D) shape, has a plurality of microphone devices mounted onto (at least one) flexible printed circuit board.
World Pat. No. 2003039014 issued to Burchard et al. discloses a piece of garment having an electronic circuit that comprises at least one unit for data acquisition and/or data output and a transmission interface.
U.S. Pat. No. 20120230526 issued to Zhang, Tao discloses a first microphone to produce a first output signal; a second microphone to produce a second output signal; a first directional filter; a first directional output signal; a digital signal processor; a voice detection circuit; a mismatch filter; a second directional filter; and a first summing circuit.
While a multitude of bidirectional microphone systems are present in the prior art, no prior art solution exists to provide a bidirectional microphone system that can be incorporated into a wearable garment, calibrate directionality and time delay at an individual microphone level, and process a high definition digital audio output of a user's voice in high ambient noise environments. Through applied effort, ingenuity and innovation, Applicant has developed a solution embodied by the present disclosure to improve upon the challenges associated with bidirectional microphones in wearable garments.